The performance of talc in peroxide cured compounds can be enhanced via surface treatment with silane coupling agents. This approach offers a method of increasing the use of talc as a reinforcing pigment to extend carbon black as well as to increase the range of application in aggressive environments. The results of DOE in an EPDM hose compound indicated that 50 percent of the carbon black could be replaced without affecting the properties. In a second study, the substitution of surface-treated talc for 50% of the carbon black improved the resistance of a HNBR compound to flex fuels.
An ultra-fine, silane-treated talc exhibited equivalent mechanical properties to a reinforcing precipitated silica and provided superior thermal aging in HNBR. Silane-treated talc provides an alternative to standard treated calcined clay in primary insulation for medium voltage industrial cable. This paper provides supporting evidence for the use of talc in peroxide cured rubber compounds to meet the demanding requirements of today.
By By Oscar F. Noel III* and Dr. Gilles Meli